Refactor validate_mac_address method

Author: eumiro

pydantic_extra_types/mac_address.py

@@ -63,58 +63,36 @@ def _validate(cls, __input_value: str, _: Any) -> str:
     @staticmethod
     def validate_mac_address(value: bytes) -> str:
         """Validate a MAC Address from the provided byte value."""
-        if len(value) < 14:
+        string = value.decode()
+        if len(string) < 14:
             raise PydanticCustomError(
                 'mac_address_len',
                 'Length for a {mac_address} MAC address must be {required_length}',
-                {'mac_address': value.decode(), 'required_length': 14},
+                {'mac_address': string, 'required_length': 14},
             )
-
-        if value[2] in [ord(':'), ord('-')]:
-            if (len(value) + 1) % 3 != 0:
-                raise PydanticCustomError(
-                    'mac_address_format', 'Must have the format xx:xx:xx:xx:xx:xx or xx-xx-xx-xx-xx-xx'
-                )
-            n = (len(value) + 1) // 3
-            if n not in (6, 8, 20):
-                raise PydanticCustomError(
-                    'mac_address_format',
-                    'Length for a {mac_address} MAC address must be {required_length}',
-                    {'mac_address': value.decode(), 'required_length': (6, 8, 20)},
-                )
-            mac_address = bytearray(n)
-            x = 0
-            for i in range(n):
-                try:
-                    byte_value = int(value[x : x + 2], 16)
-                    mac_address[i] = byte_value
-                    x += 3
-                except ValueError as e:
-                    raise PydanticCustomError('mac_address_format', 'Unrecognized format') from e
-
-        elif value[4] == ord('.'):
-            if (len(value) + 1) % 5 != 0:
-                raise PydanticCustomError('mac_address_format', 'Must have the format xx.xx.xx.xx.xx.xx')
-            n = 2 * (len(value) + 1) // 5
-            if n not in (6, 8, 20):
-                raise PydanticCustomError(
-                    'mac_address_format',
-                    'Length for a {mac_address} MAC address must be {required_length}',
-                    {'mac_address': value.decode(), 'required_length': (6, 8, 20)},
-                )
-            mac_address = bytearray(n)
-            x = 0
-            for i in range(0, n, 2):
-                try:
-                    byte_value = int(value[x : x + 2], 16)
-                    mac_address[i] = byte_value
-                    byte_value = int(value[x + 2 : x + 4], 16)
-                    mac_address[i + 1] = byte_value
-                    x += 5
-                except ValueError as e:
-                    raise PydanticCustomError('mac_address_format', 'Unrecognized format') from e
-
+        for sep, partbytes in ((':', 2), ('-', 2), ('.', 4)):
+            if sep in string:
+                parts = string.split(sep)
+                if any(len(part) != partbytes for part in parts):
+                    raise PydanticCustomError(
+                        'mac_address_format',
+                        f'Must have the format xx{sep}xx{sep}xx{sep}xx{sep}xx{sep}xx',
+                    )
+                if len(parts) * partbytes // 2 not in (6, 8, 20):
+                    raise PydanticCustomError(
+                        'mac_address_format',
+                        'Length for a {mac_address} MAC address must be {required_length}',
+                        {'mac_address': string, 'required_length': (6, 8, 20)},
+                    )
+                mac_address = []
+                for part in parts:
+                    for idx in range(0, partbytes, 2):
+                        try:
+                            byte_value = int(part[idx : idx+2], 16)
+                        except ValueError as exc:
+                            raise PydanticCustomError('mac_address_format', 'Unrecognized format') from exc
+                        else:
+                            mac_address.append(byte_value)
+                return ':'.join(f'{b:02x}' for b in mac_address)
         else:
             raise PydanticCustomError('mac_address_format', 'Unrecognized format')
-
-        return ':'.join(f'{b:02x}' for b in mac_address)